who will decide which subtitles are "right" ? If someone translate and make hard work of translating, then someone will correct some strings, and other will correct 2 words (which is ok), it is OK to have only last subtitles? It is problem, if people will leave all the credits in subtitles (which I dont think they will), it will be always lead to more problems.
The ratings and downloads "decide". Not the people.
Maybe it's me, but I think OS could be more than it currently is. It's the best option to get subtitles but most of its strength is lost on tools that are not known enough (SubDownloader and the others) and on the fame of getting subtitles from other places.
Have you considered complementing the current "repository" aspect of OS with a more active part? Striking a deal with places like wikisubtitles or creating the same environment here would be a good thing.
Let's be realistic. Having 15 different subtitle files for the same movie for the same language is not helpful. Half of those are the same re-uploaded by attention whores and of the rest half are horrible machine-translated files.
If not that then at least every subtitle who's been more than 3 months online with a low rating when there are higher-rated ones should be scrapped, as it's clearly not useful (Rating 0.0 doesn't count).
Maybe it's just me but I'd rather have quality than quantity. Having a lot of subtitles for a single movie is no replacement for having one single GOOD one.
We don't have versioning here either, so there are people uploading different versions of the same subtitle as if they were different. Doesn't make any sense.
I know you like having huge numbers but the quality of OS is dropping because a lot of people are getting into subtitles. This is the reason newer sites are doing version-control.
I personally don't care about credits in subtitles. If people really insist on a credit in a subtitle then a standard for them should be decided and added to the SRT format. Otherwise stick them 5 minutes after the last so they'll be included in the file (even if they don't show).
To answer your question: If someone makes a better translation for the same movie than you did then, yes, your subtitle gets deleted. This is the way it should work anyway. If people don't like it then standards and organizations will be born to control this (which is the reason wikisubtitles.net and other subtitle organizations exist, to standardize).